Speedtech is pretty quiet overall but their N55 turbo kits are making some noise. Check out this Asian F22 BMW M235i that the owner equipped with the Speedtech N55 manifold and a BorgWarner EFR7670 turbo charger.

The numbers:

BM3 HCP Custom Map Flash Only 98+Meth 488whp / 62KGM

BM3 HCP Backend Flash + JB4 + PI Kit + E50/98ron Mix 556whp / 79KGM

Not bad right? 556 wheel horsepower is a major upgrade for this M235i and it is working well with port injection on the stock internals and a BMS JB4.